MPI director compliance Dean Baigent said this, combined with other information gathered by MPI, suggested there had been a ''thriving'' black market in Kaikoura for some time.

''Recreational fishers have been fishing in a pseudo-commercial way and selling their catch to supply a large black market including locals, tourists, hotels and restaurants and businesses further afield,'' he said.

The retail price for rock lobster was about $90 per kilogram, which was usually about two rock lobster of legal size.